Rich, i thought about a pair of Beyerdynamic’s. I called HeadRoom and talked to a guy on the phone for about a half hour. As we were talking and he was getting the over all picture, he said that the Beyerdynamic’s would not be as ideal as a closed headphone, due to the lack of noise isolation. This is part of what killed the Grado idea as well, in addition to the overall lack of build quality.

What are your thoughts of using Beyerdynamic’s in an office environment?

The 990's are an open design. So an office environment could work as long as you don't have other people around you that may get irritated from the din.